Revisiting Nickel-Copper-Zirconia-Hydrogen Systems in Low Energy Nuclear Reactions: Toward a Unified Framework Based on Electron Catalysis and Nuclear Data

The Low Energy Nuclear Reactions (LENR) community has accumulated a significant body of experimental evidence indicating anomalous effects in metal-hydrogen systems, particularly involving nickel, copper, and hydrogen. However, many of these experiments are accompanied by unresolved questions related to so-called “mysterious catalysts,” “secret ingredients,” or trace elements believed to trigger nuclear activity. Despite these uncertainties, mainstream nuclear physics offers a wealth of wellestablished nuclear data on the isotopes present in these systems, which remains largely underdeveloped in LENR research. In this paper, we propose a new approach that integrates the empirical findings of the LENR community with nuclear physics data, guided by Edward Teller’s concept of electron catalysis. Teller suggested that under specific conditions, electrons could facilitate the formation of neutral composite particles capable of overcoming the Coulomb barrier and initiating nuclear reactions at low energies. We outline how this theoretical framework may explain key experimental observations in Ni/Cu/Zr/H systems and provide a roadmap for future quantitative studies of reaction channels, energy balance, and reaction products. This approach may open new perspective on nuclear processes occurring at the femtometer scale within condensed matter environments.

Introduction

The study of Low Energy Nuclear Reactions (LENR) has persisted as a controversial yet intriguing area of research for over three decades, e.g., [1]–[25]. In particular, systems based on nickel, copper, and hydrogen have attracted considerable attention due to experimental reports of excess heat production, isotopic shifts, and possible nuclear transmutations occurring under relatively mild conditions, e.g., [26]–[44]. While the LENR community has accumulated valuable empirical data on these phenomena, many aspects of the reported reactions remain unclear, especially the roles attributed to so-called “mysterious catalysts” or “trace ingredients” believed to trigger nuclear activity.

A major limitation of current LENR studies is the absence of a universally accepted theoretical framework capable of interpreting these experimental results. In contrast, mainstream nuclear physics offers comprehensive and precise knowledge of the nuclear properties of all isotopes present in Ni/Cu/Zr/H systems. However, these data have rarely been applied to the interpretation of LENR anomalies, primarily due to the lack of a bridging theoretical model.

In this paper, we propose that Edward Teller’s concept of electron catalysis [45], formulated in 1989 as a potential explanation for cold fusion phenomena, offers a valuable guiding principle for the study of LENR in Ni/Cu/Zr/H systems. Teller’s hypothesis suggested that electrons might form neutral quasi-nuclear configurations capable of overcoming the Coulomb barrier and participating in nuclear reactions without being consumed in the process. Such a mechanism would create pathways for nuclear reactions at low energies that remain inaccessible in conventional nuclear physics but could be analyzed using its well-established nuclear data once the initiating step is understood.

We aim to demonstrate how combining LENR experimental results with nuclear physics data, under the guiding idea of electron catalysis, could allow for the formulation of quantitative reaction schemes, energy balances, and predictions of reaction products. This approach may provide a new perspective on nuclear reactions at the femtometer scale within condensed matter environments and establish a more rigorous framework for future LENR research.

Detections of He-3 in Ni-based Binary Metal Nanocomposites with Cu in Zirconia Exposed to Hydrogen Gas at Elevated Temperatures

Yamauchi et al. [44] published an excellent quantitative study where the formation of Helium-3, together with excess heat was measured for the Cu₁/Ni₇/Zr₁₄/H system (sample 3, details in that paper). The amount of formed Helium-3 was determined by the nuclear reaction analysis based on the reaction:

(1) $$\begin{array}{r}{}_1{}^{2}H+{}_2{}^{3}He\to {}_2{}^{4}He+{}_1{}^{1}H+18.354MeV\end{array}$$

where ejected energetic protons were measured using the radiation detector CR-39. Their study was guided by the theoretical model of Takahashi [27], [28], where Helium-3 is generated from 4 hydrogen/tetrahedral symmetric condensate (4H/TSC) from unstable (⁴Li)*:

(2) $$\begin{array}{l}({}_3{}^{4}Li{)}^{\ast }\to {}_2{}^{3}He+{}_1{}^{1}H+7.72MeV\\ ({}_3{}^{4}Li{)}^{\ast }\to {}_1{}^{2}H+2{}_1{}^{1}H+2.22MeV\end{array}$$

Yamauchi et al. [44] found that excess heat 5.50 × 10⁴ J/0.1 g was formed by (5.0 ± 0.5) x 10¹⁵ of He-3. This experimental value gives excess heat per one nucleus of helium-3: (68 ± 7) MeV/He-3. This experimental value is one order higher than that proposed model by Takahashi. Yamauchi et al. [44] noticed that “this does not rule out the future possibility of other model describing He-3 production.”

Beta Electrons as the Trigger of Nuclear Reactions in the Ni/Cu/H Systems

In October 1989, Teller [45] introduced a theoretical concept based on electron catalysis, aiming to provide a possible explanation for the anomalous phenomena observed in cold fusion experiments, particularly withing the femtometer-scale domain. According to his proposal, interactions between electrons and atomic nuclei could result in the creation of previously unknown neutral structures, possessing the remarkable ability to overcome the Coulomb barrier without requiring high kinetic energies. These hypothetical configurations, possibly formed by tightly bound electron-nucleus complexes, would thus enable nuclear reactions to proceed under energy conditions significantly lower than those of conventional fusion processes. A distinctive feature of Teller’s model is the catalytic role attributed to electrons—rather than being consumed during these reactions, the electrons are envisaged to act repeatedly, facilitating sustained nuclear transformations with only limited number of catalytic electrons required. This theoretical approach opens the perspective for a novel class of low-energy nuclear reactions, wherein electrons actively participate as mediators on nuclear transitions that would otherwise be strongly suppressed or forbidden under standard conditions.

The LENR reactions could be described by introducing the electron multiplication factor k that evaluates these reactions from the point of view of their three possible reaction paths:

(3) $$\begin{array}{r}\text{k}=\frac{\text{catalytic}\text{electrons}\text{out}}{\text{catalytic}\text{electrons}\text{in}}\end{array}$$

Table I summarizes three reaction scenarios that were already observed during the Fleischmann-Pons experiments.

Table I. The Electron Multiplication Factor in the Fleischmann-Pons Experiment

Electron multiplication factor k in the Fleischmann-Pons experiment	Reference
k < 1 poisonous electron catalysis	[2], [3]
1 < k < critical value—active electron catalysis	[4]–[25]
k > critical value (“a substantial portion of the cathode fused—melting point 1544°C, part of it vaporized, and the cell and contents, and part of the fume cupboard housing the experiment were destroyed”)	[1]

Table II documents that two nuclei present in the Ni/Cu/Zr/H systems might create in the system beta electrons with needed energy to react with protons and deuterons. In the begin of the reaction only a small number of beta electrons is needed. During the following nuclear reactions additional beta particles appear via beta decays of newly formed unstable nuclei. Mangan is present in the constantan wire used by Celani et al. [29] (Cu₅₅Ni₄₅Mn₁) and as a trace element in nickel. The nuclei data will be selected for the Ni/Cu/Zr system that was recently quantitatively studied in great details by Yamauchi et al. [44].

Table II. Nuclei Present in the Ni/Cu/Zr/H System that could Trigger Nuclear Reactions

${}_{29}{}^{65}Cu+{}_0{}^{1}n\to ({}_{29}{}^{66}Cu{)}^{\ast }$
$({}_{29}{}^{66}Cu{)}^{\ast }\to {}_{30}{}^{66}Zn+{}_{-1}{}^{0}e\uparrow (t_{1/2}=5.12min)$	$Q=2.13MeV$
${}_{25}{}^{55}Mn+{}_0{}^{1}n\to \left({}_{25}{}^{56}Mn\right)\ast$
${\left({}_{25}{}^{56}Mn\right)}^{\ast }\to {}_{26}{}^{56}Fe+{}_{-1}{}^{0}e\uparrow (t_{1/2}=2.58h)$	$Q=3.69MeV$
${}_1{}^{2}H+{}_{-1}{}^{0}e\to {}_0{}^{2}n$	$Q=-2.50MeV$
${}_1{}^{1}H+{}_{-1}{}^{0}e\to {}_0{}^{1}n$	$Q=-0.78MeV$

Stávek analyzed historical papers of founding fathers of nuclear physics [46]–[48] and formulated the Rutherford-Harkins-Landau-Chadwick Key [49]–[55] inspired by papers of Ernest Rutherford [56], Harkins [57]–[59], Landau [60]–[62], and Chadwick [63].

Many nuclear physicists have been studying the properties of dineutron, trineutron and tetraneutron in the last three decades, e.g. [64]–[83]. Until now the structures of those neutral nuclei proposed by Edward Teller are not known.

Nuclei with High Neutron Capture Cross Sections in the Ni/Cu/Zr/H System

The Ni/Cu/Zr/H system has to be activated using beta electrons in order to create neutrons in Ni/H nanoparticles. These neutrons freely travel throughout this system into ZrO₂ nanoparticles (the very high concentration of ZrO₂ nanoparticles in that system). Both zirconium and oxygen have low values of neutron capture cross sections. Neutrons are not captured in these small ZrO₂ nanoreactors but fuse together to form tetraneutrons. These tetraneutrons are captured by nickel-58 (nuclei with high concentration in that system and with high neutron capture cross sections)—Table III.

Table III. Neutron Capture Cross Sections of Nickel and Copper

Isotope	Abundance [%]	Thermal capture [barns]	Contribution to elemental [barns]	Percent [%]
Ni-58	68.07	4.5	3.06	69.55
Ni-60	26.22	2.9	0.76	17.27
Ni-61	1.14	2.5	0.03	0.68
Ni-62	3.64	14.5	0.53	12.05
Ni-64	0.92	1.63	0.02	0.45
Cu-63	69.15	4.52	3.13	82.37
Cu-65	30.85	2.17	0.67	17.63
Conclusion	In the Cu 1 /Ni 7 /Zr 14 /H system the most active nucleus is Ni-58

Nuclear Reactions of Nickel-58 with Tetraneutrons

Nuclei with high neutron capture cross sections, present in the Ni₇/Cu₁/Zr₁₄/H system, capture tetraneutrons and many parallel nuclear reactions occur. For the first approach we will analyze reaction between nickel-58 and tetraneutron as it is summarized in Table IV. The calculated excess heat per one nucleus of helium-3 will be compared with the experimental value published by Yamauchi et al. [44].

Table IV. Tetraneutron Capture by Nickel-58

Tetraneutron decay
${}_{28}{}^{58}Ni+{}_0{}^{4}n\to {}_{28}{}^{58}Ni+2{}_1{}^{2}H\uparrow +2{}_{-1}{}^{0}e\uparrow$	$Q=5.00MeV$
Helium-4 formation
${}_{28}{}^{58}Ni+{}_0{}^{4}n\to {}_{28}{}^{58}Ni+{}_2{}^{4}He\uparrow +2{}_{-1}{}^{0}e\uparrow$	$Q=28.83MeV$
Helium-3 formation
${}_{28}{}^{58}Ni+{}_0{}^{4}n\to {}_{28}{}^{59}Ni+{}_2{}^{3}He+2{}_{-1}{}^{0}e$	$Q=17.26MeV$
Tritium formation
${}_{28}{}^{58}Ni+{}_0{}^{4}n\to {\left({}_{29}{}^{59}Cu\right)}^{\ast }+{}_1{}^{3}H+2{}_{-1}{}^{0}eQ=12.45MeV{\left({}_{29}{}^{59}Cu\right)}^{\ast }\to {}_{28}{}^{59}Ni+{}_{+1}{}^{0}e(t_{1/2}=81.5s)$	$Q=4.28MeV$
$\text{Calculated}\text{excess}\text{heat per one helium}-3\text{is}67.82\text{MeV}/{}_2{}^3\text{He}$
Yamauchi et al. experiment [44]
$(5.0\pm 0.5)\text{x}{10}^{15}{}_2{}^3\text{He}/(5.5\times {10}^{4}J)=(68\pm 7)\text{MeV}/{}_2{}^3\text{He}$

Yamauchi et al. [44] experimentally determined excess heat per one nucleus helium-3 (68 ± 7) MeV/³He. If we analyze tetraneutron capture with nickel-58 we get the value 67.82 MeV/³He. It will be valuable to experimentally study this Cu₁/Ni₇/Zr₁₄/H system in more details: isotopic shifts, transmutations, helium-4, helium-3, and tritium formations. All present nuclei in this system might contribute to many parallel nuclear reactions.

In the theory of modern nuclear physics [84], [85], the fission parameter Z²/A was derived where Z is the proton number and A is the mass number. Based on this rule we can estimate the potential fissionability of a nucleus: the induced fission is possible for the fission parameter higher than 17:

(4) $$\begin{array}{r}{}_Z{}^{A}X\Rightarrow \frac{Z^2}{A}\ge 17\left(inducedfissionispossible\right)\end{array}$$

Therefore, for the nucleus nickel-58 the induced fission is not possible:

(5) $$\begin{array}{r}{}_{28}{}^{58}Ni\Rightarrow \frac{{28}^2}{58}=13.5\le 17\left(inducedfissionisnotpossible\right)\end{array}$$

On the other hand, the nucleus samarium-149 might be induced to become fissile:

(6) $$\begin{array}{r}{}_{62}{}^{149}Sm\Rightarrow \frac{{62}^2}{149}=25.8\ge 17\left(inducedfissionispossible\right)\end{array}$$

The Controlled Teller’s Experiment [45]

The principle of the controlled Teller’s experiment is shown in Fig. 1. During the induction period, the activated nuclei Cu-66 and Mn-56 emit beta electrons towards the Ni/H lattice. Neutrons have been formed inside this Ni/H lattice and freely migrate into the surroundings towards ZrO₂ nanoparticles, where they fuse under the formation of tetraneutrons. These tetraneutrons have been captured by nickel-58 with its high neutron capture cross section and high nuclei concentration in the system. The dominant nuclear reactions are summarized in Table IV. We can experimentally observe excess heat, isotopic shifts, transmutation, helium-3 formation, and tritium formation. The secondary beta electrons promote the sustained chain reaction. Several parallel nuclear reactions proceed, and the electron catalysts have been recycled. The formation of beta electron concentration has to be controlled during the whole process using a beta particle absorber. This controlled manipulation of the Ni/Cu/Zr/H system avoids some supercritical states with undesired situations, e.g., [1], [86]–[88].

Fig. 1. The controlled Ni₇/Cu₁/Zr₁₄/H experiment based on the Teller’s electron catalysis.

The Ni/Pd/ZrO2/D2 System with Sm2Co17 Leads to a Higher Excess Heat

In 2018, Beiting [89], [90] presented the improvement of the Ni/Pd/ZrO₂/D₂ system with the addition of magnetic powder Sm₂Co₁₇. Beiting observed a significant increase of excess heat in this system: 10 g of Zr (50.5 wt%), Ni (24.9 wt%), Pd (2.03 wt%), O (22.03 wt%) plus 10 g of Sm₂Co₁₇. This system formed excess heat equal to 3.5 MJ (± 6%) during 950 hours in that experiment. Beiting interpreted this positive influence of used magnetic powder as the influence of the magnetic field on nuclear reactions.

In our model, we assume that the present isotope samarium-149, with its high neutron capture cross section, positively contributed to higher excess heat. Table V summarizes neutron capture cross section of stable isotopes of samarium.

Table V. Neutron Capture Cross Sections of Isotopes of Samarium [91]

Isotope	Abundance [%]	Thermal capture [barns]	Contribution to elemental [barns]	Percent
Sm144	3.1	2	0.062	0.0009
Sm147	15.0	57	8.55	0.126
Sm148	11.3	3	0.339	0.005
Sm149	13.8	39690	5477	80.45
Sm150	7.4	104	7.69	0.11
Sm152	26.7	206	55.00	0.81
Sm154	22.7	5550	1259.8	18.50
Sm			6808	100

It is known from the literature that samarium-149 has the highest neutron capture cross section among the stable isotopes of samarium. We predict that we should achieve higher reproducibility and higher excess heat after the addition of samarium isotopes in compare with the Ni/Pd/D₂ system without nuclei with high neutron capture cross sections. Table VI surveys expected nuclear reactions of the isotope samarium-149 with dineutrons, trineutrons, and tetraneutrons formed in the Ni/Pd/ZrO₂/D₂ system. During the formation of helium-4, the energy 28.83 MeV is created and this energy could induce fission of samarium-149. This activated nuclei Sm-149 could become fissile and decompose into different daughter products. One such predicted fissile reaction with following beta decays of unstable nuclei is shown in Table VII. During beta decays several extra electron catalysts are formed and the electron replicability factor k has to be controlled during these reactions in order to avoid the supercritical situation.

Table VI. Samarium-149 and its Predicted Reactions with Dineutron, Trineutron and Tetraneutron

$\begin{array}{l}\text{Dineutron}\text{decay}\\ {}_{62}{}^{149}Sm+{}_0{}^{2}n\to {}_{62}{}^{149}Sm+{}_1{}^{2}H\uparrow +{}_{-1}{}^{0}e\uparrow +2.50MeV\end{array}$
$\begin{array}{l}\text{Deuteron}\text{capture}\\ {}_{62}{}^{149}Sm+{}_0{}^{2}n\to {}_{63}{}^{151}Eu+{}_{-1}{}^{0}e\uparrow +13.82MeV\end{array}$
$\begin{array}{l}\text{Trineutron}\text{decay}\\ {}_{62}{}^{149}Sm+{}_0{}^{3}n\to {}_{62}{}^{149}Sm+{}_1{}^{3}H\uparrow +{}_{-1}{}^{0}e\uparrow +8.75MeV\end{array}$
$\begin{array}{l}\text{Trineutron}\text{capture}\\ {}_{62}{}^{149}Sm+{}_0{}^{3}n\to {}_{62}{}^{152}Sm+25.51MeV\end{array}$
$\begin{array}{l}\text{Tetraneutron}\text{decay}\\ {}_{62}{}^{149}Sm+{}_0{}^{4}n\to {}_{62}{}^{149}Sm+2{}_1{}^{2}H\uparrow +2{}_{-1}{}^{0}e\uparrow +5.00MeV\end{array}$
$\begin{array}{l}\text{Helium}-4\text{formation and induced fission of Sm-149}\\ {}_{62}{}^{149}Sm+{}_0{}^{4}n\to {\left[{}_{62}{}^{149}Sm\right]}^{\ast }+{}_2{}^{4}He\uparrow +2{}_{-1}{}^{0}e\uparrow +28.83MeV\end{array}$
$\begin{array}{l}\text{Proton}\text{capture}\\ {}_{62}{}^{149}Sm+{}_0{}^{4}n\to {}_{63}{}^{149}Eu+{}_1{}^{3}H\uparrow +2{}_{-1}{}^{0}e\uparrow +14.46MeV\end{array}$
$\begin{array}{l}\text{Neutron}\text{capture}\\ {}_{62}{}^{149}Sm+{}_0{}^{4}n\to {}_{62}{}^{150}Sm+{}_2{}^{3}He\uparrow +2{}_{-1}{}^{0}e\uparrow +16.82MeV\end{array}$
Prediction for the dominant tetraneutron channel Q = 5.00 + 28.83 + 14.46 + 16.82 = 65.11 MeV/ 4 He

Table VII. The Induced Fission of Samarium-149 and One Predicted Possible Fission of the Samarium-149

${\left[{}_{62}{}^{149}Sm\right]}^{\ast }\to {}_{28}{}^{62}Ni+{\left({}_{34}{}^{87}Se\right)}^{\ast }Q=56.52MeV$
${\left({}_{34}{}^{87}Se\right)}^{\ast }\to {\left({}_{35}{}^{87}Br\right)}^{\ast }+{}_{-1}{}^{0}e\uparrow (t_{1/2}=5.50s)$
${\left({}_{35}{}^{87}Br\right)}^{\ast }\to {\left({}_{36}{}^{87}Kr\right)}^{\ast }+{}_{-1}{}^{0}e\uparrow (t_{1/2}=55.68s)$
${\left({}_{36}{}^{87}Kr\right)}^{\ast }\to {}_{37}{}^{87}Rb\left(stable\right)+{}_{-1}{}^{0}e\uparrow (t_{1/2}=76.3min)$

Triggering of Heat in the Presence of the Permanent Magnets

During the past 36 years, the LENR community collected many valuable experimental data documenting triggering effects of many variables on excess heat formation during these low energy nuclear reactions, e.g., [92], [93]. One important trigger effect is the presence of permanent magnets close to the reaction cell, e.g., [94]–[98]. It was observed that the presence of permanent magnets with the composition Sm₂Co₁₇ and Nd₂Fe₁₄B increases excess heat in those systems. Until now it is unclear if it is truly a magnetic effect that plays the dominant role in these events or some “hidden” mechanism, that was not yet discovered, is effectively masked at the femtometer size scale.

We assume that boron-10 nuclei with their neutron capture cross section 3840 barns and samarium-149 nuclei with their neutron capture cross section 39690 barns play a significant role during these nuclear processes. Boron-10 and samarium-149 can eagerly capture dineutrons, trineutrons and tetraneutrons and during the following nuclear reactions excess heat should be formed [54], [55]. Moreover, boron-10 nuclei are “hidden” during these experiments in the PYREX glass cells (4.0% B, 54.0% O, 2.8% Na, 1.1% Al, 37.7% Si, 0.3% K). Therefore, we propose to carefully evaluate all possible contributions of nuclei present in those cells during “hidden” nuclear reactions.

Conclusion: Towards a Shared Scientific Horizon

The integration of experimental findings from the LENR community with the established nuclear data of mainstream nuclear physics represents a promising path toward resolving long-standing anomalies observed in Ni/Cu/Zr/H systems. Edward Teller’s proposal of electron catalysis offers a valuable guiding concept for understanding how nuclear reactions could occur under low-energy conditions, potentially mediated by neutral composite particles formed within metal-hydrogen environments.

By applying this framework, it becomes possible to formulate specific reaction pathways, identify candidate nuclei for interaction, calculate reaction energetics, and predict observable products of these processes. Such approach bridges the gap between experimental observation and theoretical interpretation, moving the LENR field toward greater scientific credibility and reproducibility:

1. No reproducible nuclear effects without reproducible materials

2. Control the hydrogen isotopes—control the reaction

3. Trace elements are not contamination—they may be a key

4. Every nuclear reaction leaves a signature

5. Measure nuclear energy precisely—without chemical energy

6. Look for the neutral player in the nuclear orchestra

7. Propose a model of neutral particles